Passive edge guiding method and apparatus

ABSTRACT

Web handling apparatuses and methods are provided to passively control a lateral position of a moving web. The web wraps around support rollers adjacent opposed web edges. One or more guide rollers are positioned adjacent to the support rollers. The guide rollers are in rolling contact with the web edge to guide the moving, misguided web back into its desired lateral position.

BACKGROUND

In general, a functional film can be made on a process line bydelivering an uncoated web material, applying a coating composition tothe web material, and performing drying or other treatment steps toprocess the coating composition to form a coating layer on the webmaterial. The coating composition is often not coated across the fullwidth of the web material, and the uncoated margins are eventually cutoff prior to winding up the coated web product.

Rollers can be utilized to convey the web material on the process line.Thin web substrate materials can be particularly difficult to transportover or between the rollers on the process line without causingwrinkles, kinks, bagginess, and the like, and such defects cansignificantly reduce the value of the coated web product. In addition,passing very thin or delicate coatings over and through rollers candamage the coating layer, which also reduces the value of the coated webproduct to a potential customer. Various techniques for web handling aredescribed in, for example, WO2013/090134 (Swanson et al.) andWO2016/106043 (Jerry et al.).

Reducing frictional force at an interface between the surface of therollers and the surface of the web material can be helpful in reducingthese types of defects. For example, reducing the tension on the websubstrate material, changing the material on the surfaces of the rollersthat contacts the web substrate (for example, using o-rings or sleeveson the contacting surfaces of the rollers), and reducing the wrap angleat which the web substrate contacts the roller have been employed.

SUMMARY

There is a desire to precisely control the position of a moving web in across direction perpendicular to the longitudinal, or “machinedirection.” Some embodiments of the apparatus disclosed in WO2016/106043(Jerry et al.) disclose transporting a web substrate material over anarrangement of at least two support rollers in which the rollers contactthe web substrate material only at opposed edges thereof. The web wrapsthe at least two support rollers with a substantial wrap angle. Thiswrap angle is part of what allows the positioning of rollers at opposededges of the web substrate material, leaving a center region of the websubstrate material substantially unsupported by the rollers. In effect,the web material is forced into a configuration as a partial cylinder,increasing its resistance to buckling.

The present disclosure found that this buckling resistance can beexploited to provide a mechanism to steer the lateral edge of the webfor applications where precise positioning in the cross web direction isrequired. In some embodiments, one or more guide rollers can bepositioned adjacent to the support rollers to passively control alateral position of a moving web: when the guide rollers are in rollingcontact with the respective web edge(s) of the moving web along across-web or lateral direction, the web can be guided to move back toits desired lateral position. In some embodiments, the term “passivecontrol” means that the position of a guide roller can be fixed andachieve the objective of moving the misguided web back into the targetposition by exerting force on the edge of the web. In some embodiments,the position of a guide roller can be pre-adjusted to be at apredetermined position so as to be in rolling contact with the edge ofthe web.

In one aspect, the present disclosure is directed to a web handlingapparatus having first and second support rollers. A web is configuredto wrap around the first and second support rollers adjacent first andsecond web edges, respectively. The first and second support rollers arerotatable to move the web along a length direction thereof. The webhandling apparatus further includes first and second guide rollerspositioned adjacent the first and second support rollers, respectively.The first and second guide rollers are configured to control a lateralposition of the web by contacting the respective first or second edge ofthe web along a lateral direction thereof substantially perpendicular tothe length direction.

In another aspect, the present disclosure is directed to an apparatusfor transporting a web material. The apparatus includes a first supportroller positioned to contact a major surface of a web adjacent a firstedge of the web, and a second support roller positioned to contact themajor surface of the web adjacent a second edge thereof opposite thefirst edge. A first guide roller is positioned adjacent the firstsupport roller. The web wraps around the first and second supportrollers adjacent the first and second edges thereof, respectively. Thefirst guide roller is configured to be in rolling contact with the firstedge of the substrate when the web shifts laterally toward the firstguide roller.

In yet another aspect, the present disclosure is directed to a methodincluding wrapping a web around first and second support rollersadjacent opposite first and second edges of the web, respectively. Thefirst and second support rollers are rotatable to move the web along alength direction thereof. The method further includes providing a firstguide roller adjacent the first support roller, and adjusting thelateral position of the web by contacting the first guide roller to thefirst edge of the web along a lateral direction of the web substantiallyperpendicular to the length direction.

Various unexpected results and advantages are obtained in exemplaryembodiments of the disclosure. One such advantage of exemplaryembodiments of the present disclosure is that the lateral position of aweb can be precisely controlled without touching the central portion ofthe web's major surfaces. This is accomplished by positioning one ormore guide rollers adjacent to the support rollers. When a moving webshifts laterally from its desired position, the one or more guiderollers can be in rolling contact with the web edge(s) to guide the webback into its desired lateral position.

Various aspects and advantages of exemplary embodiments of thedisclosure have been summarized. The above Summary is not intended todescribe each illustrated embodiment or every implementation of thepresent certain exemplary embodiments of the present disclosure. TheDrawings and the Detailed Description that follow more particularlyexemplify certain preferred embodiments using the principles disclosedherein.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be more completely understood in consideration of thefollowing detailed description of various embodiments of the disclosurein connection with the accompanying figures, in which:

FIG. 1 is a schematic perspective view of an embodiment of a webhandling apparatus.

FIG. 2 is a schematic side view of a roller in a web handling apparatus.

FIG. 3 is a schematic perspective view of an embodiment of a webhandling apparatus.

FIG. 4 is a schematic overhead view of a die coating system including anembodiment of a web handling apparatus.

FIG. 5 is a schematic side view of a spray coating system including anembodiment of a web handling apparatus.

FIG. 6 is a web material processing system including an embodiment of aweb handling apparatus.

FIG. 7A is a perspective view of a guide roller, according to oneembodiment.

FIG. 7B is a perspective view of a guide roller including a groove,according to another embodiment.

In the drawings, like reference numerals indicate like elements. Whilethe above-identified drawing, which may not be drawn to scale, setsforth various embodiments of the present disclosure, other embodimentsare also contemplated, as noted in the Detailed Description. In allcases, this disclosure describes the presently disclosed disclosure byway of representation of exemplary embodiments and not by expresslimitations. It should be understood that numerous other modificationsand embodiments can be devised by those skilled in the art, which fallwithin the scope and spirit of this disclosure.

DETAILED DESCRIPTION

There is a desire to precisely control the position of a moving web in across direction perpendicular to the longitudinal, or “machinedirection.” Some embodiments of the apparatus disclosed in WO2016/106043(Jerry et al.) include a substantial wrap angle around the at least tworollers which contact a substrate in the form of a web of material ofindefinite length. This wrap angle is part of what allows thepositioning the rollers at opposed edges of the web substrate material,leaving a center region of the web substrate material substantiallyunsupported by the rollers. In effect, the web is forced into aconfiguration as a partial cylinder, increasing its resistance tobuckling.

The present disclosure found that this buckling resistance can beexploited to provide a mechanism to steer the lateral edge of the webfor applications where precise positioning in the cross web direction isrequired. One or more guide rollers can be positioned adjacent to thesupport rollers to passively control a lateral position of a moving web:when the guide rollers are in rolling contact with the respective webedge(s) of the moving web along a cross-web or lateral direction, theweb can be guided to move back to its desired lateral position.

Exemplary embodiments of the present disclosure may take on variousmodifications and alterations without departing from the spirit andscope of the present disclosure. Accordingly, it is to be understoodthat the embodiments of the present disclosure are not to be limited tothe following described exemplary embodiments, but is to be controlledby the limitations set forth in the claims and any equivalents thereof.

Various exemplary embodiments of the disclosure will now be describedwith particular reference to the Drawings. Exemplary embodiments of thepresent disclosure may take on various modifications and alterationswithout departing from the spirit and scope of the disclosure.Accordingly, it is to be understood that the embodiments of the presentdisclosure are not to be limited to the following described exemplaryembodiments, but are to be controlled by the limitations set forth inthe claims and any equivalents thereof.

Referring to FIG. 1, an embodiment of a portion of a web handlingapparatus 120 is illustrated. A web material 122 with a first edge 122 aand second opposed edge 122 b moves in a direction D₁. The web material122 has a length substantially longer than its width, and moves alongits length direction. In this view, components of the web handlingapparatus 120 that are shown through the transparent web material 122are depicted with lines of lighter weight for visual clarity.

The web material 122 wraps around a first support roller 130 and asecond support roller 132 adjacent the first edge 122 a and the secondedge 122 b, respectively. The support rollers each may have a widthsubstantially smaller than the width of the web material. A shaft 124 isprovided to support the first roller 130 and the second roller 132. Theweb material 122 has its surface portions 14 and 15 adjacent the firstand second edges 122 a and 122 b to move over the surfaces of thesupport rollers 130, 132, turns, and moves downstream of the supportrollers 130, 132 in a direction D₂. In some embodiments, the surfaces ofthe support rollers 130, 132 can include o-rings or sleeves to modifythe coefficient of static friction at an interface with the web material122. In some embodiments, the support rollers 130, 132 can be idlerrollers.

The support rollers 130 and 132 toe outwardly at angles θ₁ and θ₂,respectively, with respect to the direction A to produce an optimum pathfor the web material 122. While not wishing to be bound by any theory,presently available evidence indicates that the toed outward orientationof at least one of the rollers can gently pull the web material 122 in aweb-cross or lateral direction normal to its length direction (e.g., thedirection A), which can maintain tension in the web material 122 andhelp to maintain sufficient engagement between the support rollers 130,132 and the opposed surface portions 14 and 15 to transport the webmaterial 122.

In the depicted embodiment, the shaft 124 is sufficiently bowed to causeat least one of the support rollers 130, 132 to toe outwardly. It is tobe understood that the support rollers 130 and 132 can be supported bydifferent shafts and the outward angles θ₁ and θ₂ can be separatelycontrolled. It should be noted that it is not necessary that θ₁=θ₂, andθ₁ and θ₂ can be independently selected from greater than about 0° toabout 6°, or greater than about 0 to about 2°, or greater than about 0°to about 1°, or about 0.2° to about 0.8°.

The shaft 124 may be bowed using any suitable mechanical mechanism suchas, for example, a push rod, a four-bar mechanism, a cam mechanism, andthe like. In the embodiment of FIG. 1, a push rod 134, which is mountedon a support 136 and adjustable by a suitable mechanism such as athreaded bolt 138, engages the shaft 124 and moves the shaft 124 in thedirection A. The “bowing” of the shaft 124 can be modified by adjustingthe push rod 134.

The web handling apparatus 120 of FIG. 1 further includes a first guideroller 32 and a second guide roller 34 that are shown in contact withthe first edge 122 a and the second edge 122 b, respectively. The firstand second guide rollers 32 and 34 are provided to constrain thecross-web or lateral position of web material 122 by contacting therespective first or second edge 122 a or 122 b along a lateral directionthereof substantially perpendicular to the length direction A. In someembodiments, the guide rollers 32 and 34 can be supported by theirrespective shafts (not shown) substantially perpendicular to the shaft124.

The first and second guide rollers 32 and 34 each are rotatable abouttheir respective axes. See arrows 32 a and 34 a in FIG. 1. The first andsecond guide rollers 32 and 34 each have a contacting surface 32 s or 34s positioned to be in rolling contact with the respective first orsecond web edge 122 a or 122 b. Upon contacting the web edges, the guiderollers 32 and 34 can rotate as indicated by the arrows 32 a and 34 a.When the lateral position of web material 122 shifts towards one side(e.g., towards the first guide roller 32 or the second guide roller 34),the corresponding guide roller 32 or 34 can be in rolling contact withthe respective edges 122 a or 122 b of the web material 122 to guide theweb material 122 to move back to its original lateral position.

The surfaces 32 s, 34 s of the guide rollers 32, 34 in rolling contactthe web material 122 can be independently selected from a wide range ofmaterials including, for example, natural and synthetic rubber,silicone, polymeric materials, metals, and the like. In someembodiments, the surfaces 32 s, 34 s of the guide rollers 32, 34 caninclude o-rings or sleeves to modify the coefficient of static frictionat an interface with the web material 122. In some embodiments, thesurfaces 32 s, 34 s of the guide rollers 32, 34 can be independentlyshaped or modified to achieve the desired rolling contact with the webedges. Exemplary guide rollers are shown in FIGS. 7A-B and will bedescribed further below.

Surprisingly the web material 122 even with a thin thickness can endurethe contact to the guide rollers 32 or 34 without substantial bending ortearing, which may be, at least partially, attributed to that the first32 and second 34 guide rollers are positioned adjacent the first 130 andsecond 132 support rollers, respectively. In some embodiments, thelongitudinal distance d1 or d2 of the span of the web material 122between the guide roller 32/34 and the support roller 130/132 may be ina range, for example, from about 1 cm to about 10 cm. It is to beunderstood that the longitudinal distance d1 or d2 may depend on otherprocess parameters such as, for example, the width of the web material,the thickness of the web material, the stiffness of the web material,the stress applied to the web material by the support rollers, thelength of the span of the web material between adjacent support rollersalong the length direction, etc. In general, the guide rollers 32 or 34can be positioned at any suitable distance adjacent to the correspondingsupport roller as long as such rolling contact with the web edge wouldnot introduce any substantial bending or tearing in the web material122.

In the depicted embodiment, the first 32 and second 34 guide rollers areupstream of first 130 and second 132 support rollers, meaning that theadvancing web material 122 may encounter the first 32 and second 34guide rollers before it encounters the first 130 and second 132 supportrollers. This is believed to be a more convenient positioning, butplacement of guide rollers downstream of the support rollers 130 and 134is considered to be within the scope of this disclosure.

In some embodiments, one or a pair of first guide rollers can bepositioned upstream of the support rollers; one or a pair of secondguide rollers can be positioned downstream of the support rollers. Thisconfiguration can facilitate running web both forwards and backwards. Itmight be desirable to place guide rollers at the web entrance and webexit of each idler roller so that a guide roller can be alwayspositioned at the end of the web span entering the idler roller, nomatter which direction the web may be travelling.

In some embodiments, the first and second guide rollers 32 and 34 arepositioned such that a distance between the contacting surfaces 32 s, 34s is substantially the same as the width of the web material 122. Insome embodiments, the distance between the contacting surfaces 32 s, 34s may be slightly greater than the width of the web material 122 with apredetermined tolerance T, which may be in the range, for example, fromabout 0.1 mm to about 10 cm. Any possible lateral shift of the movingweb material 122 can be constrained to be smaller than the tolerance T.

It is not necessary that embodiments of apparatus 120 within the scopeof the present disclosure have both guide rollers 32 and 34. In someembodiments, only one of the guide rollers 32, 34 is provided to bepositioned adjacent to the corresponding support roller 130 or 132. Atleast one of the support rollers 130, 132 can be adjusted such that atension can be maintained in the web material 122 to prevent it fromshifting laterally toward one direction. For example, in someembodiments, angles θ₁ and θ₂ may be chosen to impart a slight biastowards a single guide roller (32, say) which can alone locate theposition of the corresponding edge (122 a).

In the depicted embodiment of FIG. 1, the pair of support rollers 130and 132 are provided to pull the web material 122 in the lateraldirection and maintain tension in the web material 122 when it turnsaround the support rollers 130 and 132. At least one of the guiderollers 32 and 34 is positioned to be in rolling contact with the edgesof the moving web material 122 when the web material 122 shiftslaterally from its desired position. Regarding the longitudinal positionof the guide roller(s), it can be positioned adjacent to thecorresponding support roller where a sufficient web tension ismaintained to prevent any substantial bending or tearing in the webmaterial caused by the rolling contact. It is to be understood that anymechanisms that can supplement or replace the support roller(s) toprovide suitable web tension can be used.

Referring to FIG. 2, a schematic side view of the embodiment of FIG. 1is illustrated so as to clarify what is meant by wrap angle. The webmaterial 122 moving in the direction D1, contacts the first roller 130of FIG. 1 at a first point A, wraps at an angle β around thecircumference of the first roller 130, and then separates from the firstroller 130 at a point B to turn and move in the direction D2. In variousembodiments, wrap angles of about 90° to about 230° have been found tobe suitable, depending on the nature of the web material 122 and processconditions.

In another embodiment shown in FIG. 3, a portion of a web handlingapparatus 200 includes a roller 230 mounted on a shaft 224. The shaft224 is mounted to or part of a roller support 250. The shaft 224 isangularly adjustable through a pivot point 252 between the rollersupport 250 and a structural mounting element 254. As shownschematically in FIG. 3, the shaft 224 can move through a wide range ofangles α in a plane including a longitudinal axis of the shaft 224 alonga direction y and a direction of travel x of a web material 222. Inother embodiments not shown in FIG. 3, the shaft 224 could also be madeangularly adjustable through a range of angles above or below the planeincluding the longitudinal axis y of the shaft 224 and the direction oftravel x of the web material 222. As the shaft 224 is adjusted throughthe angles α, the angle of contact between the roller 230 mountedthereon and the web material 222 also changes, and the shaft 224 can beadjusted to produce a desired contact angle between the roller 230 andthe web material 222. As shown in FIG. 3, the shaft 224 can be adjustedsuch that an edge 222 a of the web material approaching the firstcontacting roller 230 and moving in direction D₁ upstream of the roller230 turns about the roller 230 and moves in a direction D₂ downstream ofthe roller 230 without wrinkling, creasing or bunching.

Various configurations of support roller are described in WO2016/106043(Jerry et al.), “Edge Contact Substrate Transport Method and Apparatus,”where the support rollers contact the web substrate material only atopposed edges thereof. Positioning the rollers at opposed edges of theweb substrate material leaves a center region of the web substratematerial between the opposed edges that is un-contacted by the rollersand remains substantially unsupported by the rollers. WO2016/106043(Jerry et al.) is hereby incorporated by reference as if rewritten.

The web handling apparatus 200 of FIG. 3 further includes a guide roller36 that is shown in contact with the web edge 222 a. The guide roller 36is provided to constrain the cross-web or lateral position of webmaterial 222. In some embodiments, the guide roller 222 a can besupported by a shaft substantially perpendicular to the mounting element254.

The guide roller is rotatable about its axis. See arrow 36 a in FIG. 3.The guide roller 36 has a contacting surface 36 s to contact the webedge 222 a. Upon contacting the web edge, the guide roller 36 can rotateas indicated by the arrow 36 a. When the lateral position of webmaterial 222 shifts towards the first guide roller 36, the guide roller36 can contact the web edges 222 a, rotate, and guide the web material222 to move back to its original lateral position.

The web handling apparatuses described above can be used in a widevariety of web material processing operations. For example, a portion ofa roll-to-roll web material processing system 750 depicted in FIG. 4includes a web material handling apparatus 700 and a coating die 752. Inthe web handling apparatus 700, a web material 722 moves in a directionA and traverses an arrangement of support rollers 712, 714. The supportrollers 712, 714 rotate about a shaft 720. At least one of the supportrollers 712, 714 is toed outward and positioned at an angle θ in a planex-y with respect to a direction x normal to a longitudinal axis y of theshaft 720. In the embodiment of FIG. 4, the support roller 712 is angledat an angle θ₁ and the support roller 714 is angled at an angle θ₂ withrespect to the direction x. In various embodiments, it is not necessarythat θ₁=θ₂, and θ₁ and θ₂ can be independently selected from greaterthan about 0° to about 6°, or greater than about 0 to about 2°, orgreater than about 0° to about 1°, or about 0.2° to about 0.8°. As theweb material 722 traverses the support rollers 712, 714, the coating die752 deposits a coating composition 753 on a surface 725 of the webmaterial 722 to form a coating layer 755 thereon.

The web handling apparatus 700 further include guide rollers 732 and 734to provide web lateral position control in the cross web direction y.The guide rollers 732 and 734 may have similar structures as the guiderollers 32 and 34 of FIG. 1, and configured to control a lateralposition of the web material 722 by contacting the edges of the webalong the cross-web or lateral direction thereof, while rotating abouttheir respective axes.

In another example shown in FIG. 5, a roll-to-roll web materialprocessing system 850 includes a web material handling apparatus 800 anda spray coater 852. The web handling system 800 includes a set ofsupport rollers 802. A web material 822 wraps around the set of supportrollers 802 at the opposite web edges thereof. The set of supportrollers 802 may have a similar configuration as the support rollers ofFIG. 1 or 3. A guide roller 832 is positioned adjacent to one of thesupport rollers 802, and configured to control a lateral position of theweb material 822 by contacting the adjacent web edge along the cross-webdirection (e.g., into the paper).

As the web material 822 traverses guide roller 832 and roller 802, thespray coater 852 deposits a coating composition 853 on a surface 825 ofthe web material 822 to form a coating layer 855 thereon. The processingsystem 850 shown schematically in FIG. 5 is particularly well suited todeposition of very thin coating layers 855 or deposition of coatingcompositions on very delicate web materials 822, or both. While notwishing to be bound by any theory, presently available evidence suggeststhat reducing the number and width of rollers underlying the webmaterial 822 can reduce or substantially prevent damage to sensitivecoatings or wrinkling and creases in very thin web materials.

In another example shown in FIG. 6, a roll-to-roll web materialprocessing system 950 includes a web material handling apparatus 900 ina multi-chamber deposition apparatus 960. The web material handlingapparatus 900 includes a first set of drive rollers 902 and a second setof drive rollers 904. At least one roller in the first set of driverollers 902 and the second set of drive rollers 904 is bowed outward atan angle selected from greater than about 0° to about 6°, or greaterthan about 0 to about 2°, or greater than about 0° to about 1°, or about0.2° to about 0.8°. The web handling system 900 further includes a firstset of idler rollers 980 and a second set of idler rollers 982, eacharranged to turn a web material 922. The web material 922 wraps aroundthe rollers 902, rolls 980 and 982 at opposite travelling web spans, androllers 904. The sets of rollers 980 and 982 can be respectively angledoutwardly in a manner similar as shown in FIG. 1.

The deposition chamber apparatus 960 includes a first deposition chamber961, a third deposition chamber 963, and a second deposition chamber 962between the first deposition chamber 961 and the third depositionchamber 963. The deposition chambers 961, 962, 963 are substantiallyisolated from one another. The second deposition chamber houses thefirst set of drive rollers 902 and the second set of drive rollers 904.The first deposition chamber 961 houses the first arrangement of idlerrollers 980 and the third deposition chamber 963 houses the secondarrangement of idler rollers 982.

In some embodiments, a first coating composition enters the firstdeposition chamber 961 at the first deposition chamber inlet 991A andexits the first deposition chamber outlet 991B. As the web material 922enters the first deposition chamber 961, the first coating compositioncontacts a surface 925 of the web material 922 to form a coating layerthereon (not shown in FIG. 6). Following deposition of the first coatingcomposition on the surface 925, the web material 922 then enters thesecond deposition chamber 962, which in some embodiments contains aninert gas input via a second deposition chamber inlet 992A. A secondcoating composition enters the third deposition chamber 963 at the thirddeposition chamber inlet 993A and exits the third deposition chamberoutlet 993B. The web material enters the third deposition chamber 963and the second coating composition is applied on the first coating layerforms a coating layer overlying the first coating layer. The webmaterial then traverses the second deposition chamber 962 and the firstdeposition chamber 961 a predetermined number of additional timesforming additional layers of the first coating composition and thesecond coating composition before the completed coated article is woundup on the second set of rollers 904 in the second deposition chamber.

In another embodiment, the first coating composition and the secondcoating composition may react to form a coating layer on the surface925.

The web material handling apparatus 900 further includes one or moreguide rollers configured to passively guide the cross-web or lateralposition of the moving web material 922. In the depicted embodiment ofFIG. 6, one or a pair of first guide rollers 932 a are positionedadjacent to the idler roller 980 a, configured to be in rolling contactwith the edge(s) of the moving web material 922; one or a pair of secondguide rollers 932 b are positioned adjacent to the idler roller 982 a,configured to be in rolling contact with the edge(s) of the moving webmaterial 922. Positioning in the cross-web direction can be accomplishedvia the one or more guide rollers (e.g., 932 a and 932 b in theillustrated embodiment).

In some embodiments, it might be most effective to position one or apair of support rollers at the end of the web span approaching therespective idler rollers 980 or 982, in a similar manner as shown inFIG. 1. For example, for the web travelling in the direction indicatedby the arrows on 902, 904, the guide roller(s) 932 a are positioned asthe web approaches the idler roller 980 a. A similarly positioned guideroller would be placed on each of the idler rollers 980, 982.

In some embodiments, it might be desirable to place guide rollers atboth the web entrance and web exit of each idler roller so that a guideroller can be always positioned at the end of the web span entering theidler roller, no matter which direction the web may be travelling. Forexample, when the web travels backwards in a direction opposite to thedirection as indicated by the arrows on 902, 904, the guide roller(s)932 b are positioned as the web approaches the idler roller 982 a. Asimilarly positioned guide roller would be placed on each of the idlerrollers 980, 982.

In another embodiment, the web handling apparatuses described above maybe useful in inspection systems. Since the rollers described herein usedhave a width that is narrow relative to the width of the web material,the web material is less likely to be distorted by contacting a wideroller or system of rollers, and debris on the rollers is less likely tocontaminate the sample being inspected.

Referring now to FIGS. 7A-B, exemplary guide rollers described hereinare shown, according to some embodiments. FIG. 7A illustrates a guideroller 30 that is rotatable about its axis and has a periphery surface30 s. A bearing 35 is provided to support the guide roller 30 in rollingcontact with a web edge. When the guide roller 30 is in rolling contactwith a web edge (e.g., 122 a or 122 b in FIG. 1), the periphery surface30 s contacts the web edge along a cross-web or lateral direction tocontrol a lateral position of the web. In some embodiments, theperiphery surface 30 s can be shaped or modified to optimize the rollingcontact to the web edge.

In the embodiment of FIG. 7B, a groove 33 is formed into the peripherysurface 30 s of a guide roller 30′ to receive and further support theedge of the web against folding or buckling. The groove 33 has first andsecond opposite sides, 33 a and 33 b, and a bottom surface (not visiblein FIG. 7B). The guide roller 30′ is rotatable about its axis. Thebearing 35 to support the guide roller 30′ in rolling contact with a webedge can also be seen. When the guide roller 30′ is in rolling contactwith a web edge, the web edge (e.g., 122 a or 122 b in FIG. 1) cancontact the bottom surface of the groove 33. The sides 33 a or 33 b ofthe groove 33 may contact the surface portions of the web received bythe groove 33 to prevent possible folding or buckling. The size of thegroove 33 may depend on the desired application. In some embodiments,the groove 33 may have a depth, for example, from about 1 mm to 100 mm,from about 3 mm to 50 mm, or from about 5 mm to 30 mm; the groove 33 mayhave a width, for example, from about 5 mm to 100 mm, from about 10 mmto 50 mm, or from about 15 mm to 30 mm.

The web handling apparatuses described herein may be used to process webmaterials at a wide variety of web speeds from about 5 feet per minute(about 13 cm/sec) to about 3000 feet per minute (about 76 m/sec), andmay be used in any surrounding medium including air, inert gases, water,vacuum and the like.

In some embodiments, a control system may optionally be used to controland/or maintain the toe out angle of the rollers.

The operation of the present disclosure will be further described withregard to the following detailed example(s). These example(s) areoffered to further illustrate the various specific and preferredembodiments and techniques. It should be understood, however, that manyvariations and modifications may be made while remaining within thescope of the present disclosure.

Example

These Examples are merely for illustrative purposes and are not meant tobe overly limiting on the scope of the appended claims. Notwithstandingthat the numerical ranges and parameters setting forth the broad scopeof the present disclosure are approximations, the numerical values setforth in the specific examples are reported as precisely as possible.Any numerical value, however, inherently contains certain errorsnecessarily resulting from the standard deviation found in theirrespective testing measurements. At the very least, and not as anattempt to limit the application of the doctrine of equivalents to thescope of the claims, each numerical parameter should at least beconstrued in light of the number of reported significant digits and byapplying ordinary rounding techniques.

A web handling apparatus was constructed generally as depicted in FIG. 1with support rollers spaced apart at a distance of 14 inches (35.56 cm)and used to transport web material in the form of a web of indefinitelength. Several runs were made with polyethylene terephthalate (PET) ofdifferent thicknesses, specifically 0.13 mm, 0.076 mm, and 0.051 mm. Therollers were toed out at an angle of about greater than about 0° toabout 6°, or greater than about 0 to about 2°, or greater than about 0°to about 1°, or about 0.2° to about 0.8° as shown in FIG. 1. A webtension of 10 pound-force was applied across the span of the web (1.25N/linear cm). Guide rollers having a diameter of 1.75 inches (4.45 cm)and possessing a groove having a width of 0.605 inch (1.54 cm) and adepth of 0.25 inch (0.64 cm) were positioned 2.5 inches (6.4 cm)upstream of the support rollers, such that the web was retained withinthe groove. The web was advanced at a speed of 100 feet/min (30.5m/min). In spite of the thinness of the web and the length of theunsupported span between the support rollers, the web was conveyedsmoothly and without buckling. Further, the contact with the guiderollers was maintained without folding or buckling, such that the crossweb position of the web was constrained to a high degree of certainty.

Listing of Exemplary Embodiments

Various embodiments of the present disclosure have been described. Theseand other embodiments are within the scope of the following claims.

Embodiment A is directed to a web handling apparatus comprising:

first and second support rollers, a web being configured to wrap aroundthe first and second support rollers at first and second web edges,respectively, the first and second support rollers being rotatable tomove the web along a length direction thereof; and

first and second guide rollers positioned adjacent the first and secondsupport rollers, respectively, the first and second guide rollers beingconfigured to control a lateral position of the web by contacting therespective first or second edge of the web along a lateral directionthereof substantially perpendicular to the length direction.

Embodiment B is directed to the web handling apparatus according toEmbodiment A, wherein the web wraps around the first and second supportrollers with a wrap angle of about 90° to about 230°.

Embodiment C is directed to the web handling apparatus according toEmbodiments A or B, wherein a span of the web between the first guideroller and the first support roller has a length of about 1 cm to about10 cm.

Embodiment D is directed to the web handling apparatus according to anyof the preceding Embodiments A-C, wherein at least one of the first andsecond guide rollers includes a groove to receive the first or secondedge of the web, the groove having opposite sides configured to contactopposite major surfaces of the web at the first edge.

Embodiment E is directed to the web handling apparatus according to anyof the preceding Embodiments A-D, wherein the first and second guiderollers are positioned with a distance therebetween substantially thesame as the width of the web.

Embodiment F is directed to the web handling apparatus according to anyof the preceding Embodiments A-E, wherein the web comprises anun-contacted region between the first and the second support rollscomprising at least about 50% of the width of the web.

Embodiment G is directed to the web handling apparatus according to anyof the preceding Embodiments A-F, wherein at least one of the firstsupport roller and the second support roller is supported on the bowedshaft such that at least one of the first and second support rollers isangled outwardly with respect to a direction of web travel.

Embodiment H is directed to the web handling apparatus according to anyof the preceding Embodiments A-G, wherein the first and second supportrollers are respectively angled outwardly with an angle θ.

Embodiment I is directed to the web handling apparatus according toEmbodiment H, wherein the angle θ is adjustable in a range of about 0°to about 6°.

Embodiment J is directed to the web handling apparatus according to anyof the preceding Embodiments A-I, wherein the first and second guiderollers each are positioned at an upstream position of the respectivefirst and second support rollers.

Embodiment K is directed to an apparatus for transporting a webmaterial, the apparatus comprising:

a first support roller positioned to contact a major surface of a webadjacent a first edge of the web;

a second support roller positioned to contact the major surface of theweb adjacent a second edge thereof opposite the first edge; and

a first guide roller positioned adjacent the first support roller,

wherein the web wraps around the first and second support rollersadjacent the first and second edges thereof, respectively, and whereinthe first guide roller is configured to be in rolling contact with thefirst edge of the substrate when the web shifts laterally toward thefirst guide roller.

Embodiment L is directed to an apparatus for transporting a web materialaccording to embodiment K, further comprising a second guide rollerpositioned adjacent the second support roller, and configured to contactthe second edge of the substrate.

Embodiment M is directed to an apparatus for transporting a web materialaccording to embodiments K or L, wherein the first guide roller ispositioned at an upstream position of the first support roller.

Embodiment N is directed to a method comprising: wrapping a web aroundfirst and second support rollers adjacent opposite first and secondedges of the web, respectively, the first and second support rollersbeing rotatable to move the web along a length direction thereof;

providing a first guide roller adjacent the first support roller; and

adjusting the lateral position of the web by contacting the first guideroller to the first edge of the web along a lateral direction of the websubstantially perpendicular to the length direction.

Embodiment O is directed to the method according to Embodiment N,further comprising providing a groove to the first guide roller toreceive the first edge of the web, the groove has opposite sidesconfigured to contact opposite major surfaces of the web at the firstedge.

Embodiment P is directed to the method according to Embodiments N or O,wherein a central region of the web between the first support roller andthe second support roller comprising at least about 80% of a width ofthe web is free of support from a roller.

Embodiment Q is directed to the method according to Embodiments N-P,wherein the web wraps about the first roller and the second roller at anangle of about 90° to about 230°.

Embodiment R is directed to the method according to Embodiments N-Q,further comprising orienting at least one of the first and secondsupport rollers at an angle θ in a plane x-y with respect to the lengthdirection x normal to the width direction y of the web, and wherein theangle θ is adjustable in a range of about 0° to about 6°.

Embodiment S is directed to the method according to Embodiments N-R,further comprising positioning a second guide roller adjacent the secondsupport roller to contact the second edge of the web.

Embodiment T is directed to the method according to Embodiments N-S,further comprising applying a coating composition on the web, andprocessing the coating composition to form a coating layer on the web.

Reference throughout this specification to “one embodiment,” “certainembodiments,” “one or more embodiments” or “an embodiment,” whether ornot including the term “exemplary” preceding the term “embodiment,”means that a particular feature, structure, material, or characteristicdescribed in connection with the embodiment is included in at least oneembodiment of the certain exemplary embodiments of the presentdisclosure. Thus, the appearances of the phrases such as “in one or moreembodiments,” “in certain embodiments,” “in one embodiment” or “in anembodiment” in various places throughout this specification are notnecessarily referring to the same embodiment of the certain exemplaryembodiments of the present disclosure. Furthermore, the particularfeatures, structures, materials, or characteristics may be combined inany suitable manner in one or more embodiments.

While the specification has described in detail certain exemplaryembodiments, it will be appreciated that those skilled in the art, uponattaining an understanding of the foregoing, may readily conceive ofalterations to, variations of, and equivalents to these embodiments.Accordingly, it should be understood that this disclosure is not to beunduly limited to the illustrative embodiments set forth hereinabove. Inparticular, as used herein, the recitation of numerical ranges byendpoints is intended to include all numbers subsumed within that range(e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). In addition,all numbers used herein are assumed to be modified by the term “about.”

Furthermore, all publications and patents referenced herein areincorporated by reference in their entirety to the same extent as ifeach individual publication or patent was specifically and individuallyindicated to be incorporated by reference. Various exemplary embodimentshave been described. These and other embodiments are within the scope ofthe following claims.

1. A web handling apparatus comprising: first and second supportrollers, a web being configured to wrap around the first and secondsupport rollers adjacent first and second web edges thereof,respectively, the first and second support rollers being rotatable tomove the web along a length direction thereof; and first and secondguide rollers positioned adjacent the first and second support rollers,respectively, the first and second guide rollers being configured tocontrol a lateral position of the web by contacting the respective firstor second web edge along a lateral direction thereof substantiallyperpendicular to the length direction.
 2. The web handling apparatus ofclaim 1, wherein the web wraps around the first and second supportrollers with a wrap angle of about 90° to about 230°.
 3. The webhandling apparatus of claim 1, wherein a span of the web between thefirst guide roller and the first support roller has a length of about 1cm to about 10 cm.
 4. The web handling apparatus of claim 1, wherein atleast one of the first and second guide rollers includes a groove toreceive the first or second edge of the web, the groove has oppositesides configured to contact opposite major surfaces of the web at thefirst edge.
 5. The web handling apparatus of claim 1, wherein the firstand second guide rollers are positioned with a distance therebetweensubstantially the same as the width of the web.
 6. The web handlingapparatus of claim 1, wherein the web comprises an un-contacted regionbetween the first and the second support rolls comprising at least about50% of the width of the web.
 7. The web handling apparatus of claim 1further comprises a bowed shaft, wherein at least one of the firstsupport roller and the second support roller is supported on the bowedshaft such that at least one of the first and second support rollers isangled outwardly with respect to a direction of web travel.
 8. The webhandling apparatus of claim 1, wherein the first and second supportrollers are respectively angled outwardly with an angle θ.
 9. The webhandling apparatus of claim 8, wherein the angle θ is adjustable in arange of about 0° to about 6°.
 10. The web handling apparatus of claim1, wherein the first and second guide rollers each are positioned at anupstream position of the respective first and second support rollers.11. An apparatus for transporting a web material, the apparatuscomprising: a first support roller positioned to contact a major surfaceof a web adjacent a first edge of the web; a second support rollerpositioned to contact the major surface of the web adjacent a secondedge thereof opposite the first edge; and a first guide rollerpositioned adjacent the first support roller, wherein the web wrapsaround the first and second support rollers adjacent the first andsecond edges thereof, respectively, and wherein the first guide rolleris configured to be in rolling contact with the first edge of the webwhen the web shifts laterally toward the first guide roller.
 12. Theapparatus of claim 11 further comprising a second guide rollerpositioned adjacent the second support roller, and the second guideroller being configured to contact the second edge of the web.
 13. Theapparatus of claim 11, wherein the first guide roller is positioned atan upstream position of the first support roller.
 14. A methodcomprising: wrapping a web around first and second support rollersadjacent opposite first and second edges of the web, respectively, thefirst and second support rollers being rotatable to move the web along alength direction thereof; providing a first guide roller adjacent thefirst support roller; and adjusting the lateral position of the web bycontacting the first guide roller to the first edge of the web along alateral direction of the web substantially perpendicular to the lengthdirection.
 15. The method of claim 14 further comprising providing agroove to the first guide roller to receive the first edge of the web,the groove has opposite sides configured to contact opposite majorsurfaces of the web at the first edge.
 16. The method of claim 14,wherein a central region of the web between the first support roller andthe second support roller comprising at least about 80% of a width ofthe web is free of support from a roller.
 17. The method of claim 14,wherein the web wraps about the first roller and the second roller at anangle of about 90° to about 230°.
 18. The method of claim 14 furthercomprising orienting at least one of the first and second supportrollers at an angle θ in a plane x-y with respect to the lengthdirection x normal to the width direction y of the web, and wherein theangle θ is adjustable in a range of about 0° to about 6°.
 19. The methodof claim 14 further comprising positioning a second guide rolleradjacent the second support roller to contact the second edge of theweb.
 20. The method of claim 14 further comprising applying a coatingcomposition on the web, and processing the coating composition to form acoating layer on the web.